<?php
/*
 * Project:    template_lite, a smarter template engine
 * File:    class.compiler.php
 * Author:    Paul Lockaby <paul@paullockaby.com>, Mark Dickenson <akapanamajack@sourceforge.net>
 * Copyright:    2003,2004,2005 by Paul Lockaby, 2005,2006 Mark Dickenson
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * The latest version of template_lite can be obtained from:
 * http://templatelite.sourceforge.net
 *
 */

class Template_Lite_Compiler extends Template_Lite {
    // public configuration variables
    var $left_delimiter            = "";
    var $right_delimiter            = "";
    var $plugins_dir            = "";
    var $template_dir        = "";
    var $reserved_template_varname = "";
    var $default_modifiers        = array();

    var $php_extract_vars        =    true;    // Set this to false if you do not want the $this->_tpl variables to be extracted for use by PHP code inside the template.

    // private internal variables
    var $_vars            =    array();    // stores all internal assigned variables
    var $_confs            =    array();    // stores all internal config variables
    var $_plugins            =    array();    // stores all internal plugins
    var $_linenum            =    0;        // the current line number in the file we are processing
    var $_file            =    "";        // the current file we are processing
    var $_literal            =    array();    // stores all literal blocks
    var $_foreachelse_stack        =    array();
    var $_for_stack            =    0;
    var $_sectionelse_stack     =   array();    // keeps track of whether section had 'else' part
    var $_switch_stack        =    array();
    var $_tag_stack            =    array();
    var $_require_stack        =    array();    // stores all files that are "required" inside of the template
    var $_php_blocks        =    array();    // stores all of the php blocks
    var $_error_level        =    null;
    var $_sl_md5            =    '39fc70570b8b60cbc1b85839bf242aff';

    var $_db_qstr_regexp        =    null;        // regexps are setup in the constructor
    var $_si_qstr_regexp        =    null;
    var $_qstr_regexp        =    null;
    var $_func_regexp        =    null;
    var $_var_bracket_regexp    =    null;
    var $_dvar_regexp        =    null;
    var $_cvar_regexp        =    null;
    var $_svar_regexp        =    null;
    var $_mod_regexp        =    null;
    var $_var_regexp        =    null;
    var $_obj_params_regexp     =   null;
    var $_templatelite_vars        =    array();

    function Template_Lite_compiler()
    {
        // matches double quoted strings:
        // "foobar"
        // "foo\"bar"
        // "foobar" . "foo\"bar"
        $this->_db_qstr_regexp = '"[^"\\\\]*(?:\\\\.[^"\\\\]*)*"';

        // matches single quoted strings:
        // 'foobar'
        // 'foo\'bar'
        $this->_si_qstr_regexp = '\'[^\'\\\\]*(?:\\\\.[^\'\\\\]*)*\'';

        // matches single or double quoted strings
        $this->_qstr_regexp = '(?:' . $this->_db_qstr_regexp . '|' . $this->_si_qstr_regexp . ')';

        // matches bracket portion of vars
        // [0]
        // [foo]
        // [$bar]
        // [#bar#]
        $this->_var_bracket_regexp = '\[[\$|\#]?\w+\#?\]';
//        $this->_var_bracket_regexp = '\[\$?[\w\.]+\]';

        // matches section vars:
        // %foo.bar%
        $this->_svar_regexp = '\%\w+\.\w+\%';

        // matches $ vars (not objects):
        // $foo
        // $foo[0]
        // $foo[$bar]
        // $foo[5][blah]
//        $this->_dvar_regexp = '\$[a-zA-Z0-9_]{1,}(?:' . $this->_var_bracket_regexp . ')*(?:' . $this->_var_bracket_regexp . ')*';
        $this->_dvar_regexp = '\$[a-zA-Z0-9_]{1,}(?:' . $this->_var_bracket_regexp . ')*(?:\.\$?\w+(?:' . $this->_var_bracket_regexp . ')*)*';

        // matches config vars:
        // #foo#
        // #foobar123_foo#
        $this->_cvar_regexp = '\#[a-zA-Z0-9_]{1,}(?:' . $this->_var_bracket_regexp . ')*(?:' . $this->_var_bracket_regexp . ')*\#';

        // matches valid variable syntax:
        // $foo
        // 'text'
        // "text"
        $this->_var_regexp = '(?:(?:' . $this->_dvar_regexp . '|' . $this->_cvar_regexp . ')|' . $this->_qstr_regexp . ')';

        // matches valid modifier syntax:
        // |foo
        // |@foo
        // |foo:"bar"
        // |foo:$bar
        // |foo:"bar":$foobar
        // |foo|bar
        $this->_mod_regexp = '(?:\|@?[0-9a-zA-Z_]+(?::(?>-?\w+|' . $this->_dvar_regexp . '|' . $this->_qstr_regexp .'))*)';        

        // matches valid function name:
        // foo123
        // _foo_bar
        $this->_func_regexp = '[a-zA-Z_]+';
//        $this->_func_regexp = '[a-zA-Z_]\w*';

    }

    function _compile_file($file_contents)
    {
        $ldq = preg_quote($this->left_delimiter);
        $rdq = preg_quote($this->right_delimiter);
        $_match        = array();        // a temp variable for the current regex match
        $tags        = array();        // all original tags
        $text        = array();        // all original text
        $compiled_text    = '<?php /* '.$this->_version.' '.strftime("%Y-%m-%d %H:%M:%S %Z").' */ ?>'."\n\n"; // stores the compiled result
        $compiled_tags    = array();        // all tags and stuff

        $this->_require_stack = array();

        $this->_load_filters();

        if (count($this->_plugins['prefilter']) > 0)
        {
            foreach ($this->_plugins['prefilter'] as $function)
            {
                if ($function === false)
                {
                    continue;
                }
                $file_contents = $function($file_contents, $this);
            }
        }

        // remove all comments
        $file_contents = preg_replace("!{$ldq}\*.*?\*{$rdq}!se","",$file_contents);

        // replace all php start and end tags
        $file_contents = preg_replace('%(<\?(?!php|=|$))%i', '<?php echo \'\\1\'?>'."\n", $file_contents);

        // remove literal blocks
        preg_match_all("!{$ldq}\s*literal\s*{$rdq}(.*?){$ldq}\s*/literal\s*{$rdq}!s", $file_contents, $_match);
        $this->_literal = $_match[1];
        $file_contents = preg_replace("!{$ldq}\s*literal\s*{$rdq}(.*?){$ldq}\s*/literal\s*{$rdq}!s", stripslashes($ldq . "literal" . $rdq), $file_contents);

        // remove php blocks
        preg_match_all("!{$ldq}\s*php\s*{$rdq}(.*?){$ldq}\s*/php\s*{$rdq}!s", $file_contents, $_match);
        $this->_php_blocks = $_match[1];
        $file_contents = preg_replace("!{$ldq}\s*php\s*{$rdq}(.*?){$ldq}\s*/php\s*{$rdq}!s", stripslashes($ldq . "php" . $rdq), $file_contents);

        // gather all template tags
        preg_match_all("!{$ldq}\s*(.*?)\s*{$rdq}!s", $file_contents, $_match);
        $tags = $_match[1];

        // put all of the non-template tag text blocks into an array, using the template tags as delimiters
        $text = preg_split("!{$ldq}.*?{$rdq}!s", $file_contents);

        // compile template tags
        $count_tags = count($tags);
        for ($i = 0, $for_max = $count_tags; $i < $for_max; $i++)
        {
            $this->_linenum += substr_count($text[$i], "\n");
            $compiled_tags[] = $this->_compile_tag($tags[$i]);
            $this->_linenum += substr_count($tags[$i], "\n");
        }

        // build the compiled template by replacing and interleaving text blocks and compiled tags
        $count_compiled_tags = count($compiled_tags);
        for ($i = 0, $for_max = $count_compiled_tags; $i < $for_max; $i++)
        {
            if ($compiled_tags[$i] == '') {
                $text[$i+1] = preg_replace('~^(\r\n|\r|\n)~', '', $text[$i+1]);
            }
            $compiled_text .= $text[$i].$compiled_tags[$i];
        }
        $compiled_text .= $text[$i];

        foreach ($this->_require_stack as $key => $value)
        {
            $compiled_text = '<?php require_once(\''. $this->_get_plugin_dir($key) . $key . '\'); $this->register_' . $value[0] . '("' . $value[1] . '", "' . $value[2] . '"); ?>' . $compiled_text;
        }

        // remove unnecessary close/open tags
        $compiled_text = preg_replace('!\?>\n?<\?php!', '', $compiled_text);

        if (count($this->_plugins['postfilter']) > 0)
        {
            foreach ($this->_plugins['postfilter'] as $function)
            {
                if ($function === false)
                {
                    continue;
                }
                $compiled_text = $function($compiled_text, $this);
            }
        }

        return $compiled_text;
    }

    function _compile_tag($tag)
    {
        $_match        = array();        // stores the tags
        $_result    = "";            // the compiled tag
        $_variable    = "";            // the compiled variable

        // extract the tag command, modifier and arguments
        preg_match_all('/(?:(' . $this->_var_regexp . '|' . $this->_svar_regexp . '|\/?' . $this->_func_regexp . ')(' . $this->_mod_regexp . '*)(?:\s*[,\.]\s*)?)(?:\s+(.*))?/xs', $tag, $_match);

        if ($_match[1][0]{0} == '$' || ($_match[1][0]{0} == '#' && $_match[1][0]{strlen($_match[1][0]) - 1} == '#') || $_match[1][0]{0} == "'" || $_match[1][0]{0} == '"' || $_match[1][0]{0} == '%')
        {
            $_result = $this->_parse_variables($_match[1], $_match[2]);
            return "<?php echo $_result; ?>\n";
        }
        // process a function
        $tag_command = $_match[1][0];
        $tag_modifiers = !empty($_match[2][0]) ? $_match[2][0] : null;
        $tag_arguments = !empty($_match[3][0]) ? $_match[3][0] : null;
        $_result = $this->_parse_function($tag_command, $tag_modifiers, $tag_arguments);
        return $_result;
    }

    function _parse_function($function, $modifiers, $arguments)
    {
        switch ($function) {
            case 'include':
                if (!function_exists('compile_include'))
                {
                    require_once(TEMPLATE_LITE_DIR . "internal/compile.include.php");
                }
                return compile_include($arguments, $this);
                break;
            case 'insert':
                $_args = $this->_parse_arguments($arguments);
                if (!isset($_args['name']))
                {
                    $this->trigger_error("missing 'name' attribute in 'insert'", E_USER_ERROR, __FILE__, __LINE__);
                }
                foreach ($_args as $key => $value)
                {
                    if (is_bool($value))
                    {
                        $value = $value ? 'true' : 'false';
                    }
                    $arg_list[] = "'$key' => $value";
                }
                return '<?php echo $this->_run_insert(array(' . implode(', ', (array)$arg_list) . ')); ?>';
                break;
            case 'ldelim':
                return $this->left_delimiter;
                break;
            case 'rdelim':
                return $this->right_delimiter;
                break;
            case 'literal':
                list (,$literal) = each($this->_literal);
                $this->_linenum += substr_count($literal, "\n");
                return "<?php echo '" . str_replace("'", "\'", str_replace("\\", "\\\\", $literal)) . "'; ?>\n";
                break;
            case 'php':
                list (,$php_block) = each($this->_php_blocks);
                $this->_linenum += substr_count($php_block, "\n");
                $php_extract = '';
                if($this->php_extract_vars)
                {
                    if (strnatcmp(PHP_VERSION, '4.3.0') >= 0)
                    {
                        $php_extract = '<?php extract($this->_vars, EXTR_REFS); ?>' . "\n";
                    }
                    else
                    {
                        $php_extract = '<?php extract($this->_vars); ?>' . "\n";
                    }
                }
                return $php_extract . '<?php '.$php_block.' ?>';
                break;
            case 'foreach':
                array_push($this->_foreachelse_stack, false);
                $_args = $this->_parse_arguments($arguments);
                if (!isset($_args['from']))
                {
                    $this->trigger_error("missing 'from' attribute in 'foreach'", E_USER_ERROR, __FILE__, __LINE__);
                }
                if (!isset($_args['value']) && !isset($_args['item']))
                {
                    $this->trigger_error("missing 'value' attribute in 'foreach'", E_USER_ERROR, __FILE__, __LINE__);
                }
                if (isset($_args['value']))
                {
                    $_args['value'] = $this->_dequote($_args['value']);
                }
                elseif (isset($_args['item']))
                {
                    $_args['value'] = $this->_dequote($_args['item']);
                }
                isset($_args['key']) ? $_args['key'] = "\$this->_vars['".$this->_dequote($_args['key'])."'] => " : $_args['key'] = '';
                $_result = '<?php if (count((array)' . $_args['from'] . ')): foreach ((array)' . $_args['from'] . ' as ' . $_args['key'] . '$this->_vars[\'' . $_args['value'] . '\']): ?>';
                return $_result;
                break;
            case 'foreachelse':
                $this->_foreachelse_stack[count($this->_foreachelse_stack)-1] = true;
                return "<?php endforeach; else: ?>";
                break;
            case '/foreach':
                if (array_pop($this->_foreachelse_stack))
                {
                    return "<?php endif; ?>";
                }
                else
                {
                    return "<?php endforeach; endif; ?>";
                }
                break;
            case 'for':
                $this->_for_stack++;
                $_args = $this->_parse_arguments($arguments);
                if (!isset($_args['start']))
                {
                    $this->trigger_error("missing 'start' attribute in 'for'", E_USER_ERROR, __FILE__, __LINE__);
                }
                if (!isset($_args['stop']))
                {
                    $this->trigger_error("missing 'stop' attribute in 'for'", E_USER_ERROR, __FILE__, __LINE__);
                }
                if (!isset($_args['step']))
                {
                    $_args['step'] = 1;
                }
                $_result = '<?php for($for' . $this->_for_stack . ' = ' . $_args['start'] . '; ((' . $_args['start'] . ' < ' . $_args['stop'] . ') ? ($for' . $this->_for_stack . ' < ' . $_args['stop'] . ') : ($for' . $this->_for_stack . ' > ' . $_args['stop'] . ')); $for' . $this->_for_stack . ' += ((' . $_args['start'] . ' < ' . $_args['stop'] . ') ? ' . $_args['step'] . ' : -' . $_args['step'] . ')): ?>';
                if (isset($_args['value']))
                {
                    $_result .= '<?php $this->assign(\'' . $this->_dequote($_args['value']) . '\', $for' . $this->_for_stack . '); ?>';
                }
                return $_result;
                break;
            case '/for':
                $this->_for_stack--;
                return "<?php endfor; ?>";
                break;
            case 'section':
                array_push($this->_sectionelse_stack, false);
                if (!function_exists('compile_section_start'))
                {
                    require_once(TEMPLATE_LITE_DIR . "internal/compile.section_start.php");
                }
                return compile_section_start($arguments, $this);
                break;
            case 'sectionelse':
                $this->_sectionelse_stack[count($this->_sectionelse_stack)-1] = true;
                return "<?php endfor; else: ?>";
                break;
            case '/section':
                if (array_pop($this->_sectionelse_stack))
                {
                    return "<?php endif; ?>";
                }
                else
                {
                    return "<?php endfor; endif; ?>";
                }
                break;
            case 'while':
                $_args = $this->_compile_if($arguments, false, true);
                return '<?php while(' . $_args . '): ?>';
                break;
            case '/while':
                return "<?php endwhile; ?>";
                break;
            case 'if':
                return $this->_compile_if($arguments);
                break;
            case 'else':
                return "<?php else: ?>";
                break;
            case 'elseif':
                return $this->_compile_if($arguments, true);
                break;
            case '/if':
                return "<?php endif; ?>";
                break;
            case 'assign':
                $_args = $this->_parse_arguments($arguments);
                if (!isset($_args['var']))
                {
                    $this->trigger_error("missing 'var' attribute in 'assign'", E_USER_ERROR, __FILE__, __LINE__);
                }
                if (!isset($_args['value']))
                {
                    $this->trigger_error("missing 'value' attribute in 'assign'", E_USER_ERROR, __FILE__, __LINE__);
                }
                return '<?php $this->assign(\'' . $this->_dequote($_args['var']) . '\', ' . $_args['value'] . '); ?>';
                break;
            case 'switch':
                $_args = $this->_parse_arguments($arguments);
                if (!isset($_args['from']))
                {
                    $this->trigger_error("missing 'from' attribute in 'switch'", E_USER_ERROR, __FILE__, __LINE__);
                }
                array_push($this->_switch_stack, array("matched" => false, "var" => $this->_dequote($_args['from'])));
                return;
                break;
            case '/switch':
                array_pop($this->_switch_stack);
                return '<?php break; endswitch; ?>';
                break;
            case 'case':
                if (count($this->_switch_stack) > 0)
                {
                    $_result = "<?php ";
                    $_args = $this->_parse_arguments($arguments);
                    $_index = count($this->_switch_stack) - 1;
                    if (!$this->_switch_stack[$_index]["matched"])
                    {
                        $_result .= 'switch(' . $this->_switch_stack[$_index]["var"] . '): ';
                        $this->_switch_stack[$_index]["matched"] = true;
                    }
                    else
                    {
                        $_result .= 'break; ';
                    }
                    if (!empty($_args['value']))
                    {
                        $_result .= 'case '.$_args['value'].': ';
                    }
                    else
                    {
                        $_result .= 'default: ';
                    }
                    return $_result . ' ?>';
                }
                else
                {
                    $this->trigger_error("unexpected 'case', 'case' can only be in a 'switch'", E_USER_ERROR, __FILE__, __LINE__);
                }
                break;
            case 'config_load':
                $_args = $this->_parse_arguments($arguments);
                if (empty($_args['file']))
                {
                    $this->trigger_error("missing 'file' attribute in 'config_load' tag", E_USER_ERROR, __FILE__, __LINE__);
                }
                isset($_args['section']) ? null : $_args['section'] = 'null';
                isset($_args['var']) ? null : $_args['var'] = 'null';
                return '<?php $this->config_load(' . $_args['file'] . ', ' . $_args['section'] . ', ' . $_args['var'] . '); ?>';
                break;
            default:
                $_result = "";
                if ($this->_compile_compiler_function($function, $arguments, $_result))
                {
                    return $_result;
                }
                else if ($this->_compile_custom_block($function, $modifiers, $arguments, $_result))
                {
                    return $_result;
                }
                elseif ($this->_compile_custom_function($function, $modifiers, $arguments, $_result))
                {
                    return $_result;
                }
                else
                {
                    $this->trigger_error($function." function does not exist", E_USER_ERROR, __FILE__, __LINE__);
                }
                break;
        }
    }

    function _compile_compiler_function($function, $arguments, &$_result)
    {
        if ($function = $this->_plugin_exists($function, "compiler"))
        {
            $_args = $this->_parse_arguments($arguments);
            $_result = '<?php ' . $function($_args, $this) . ' ?>';
            return true;
        }
        else
        {
            return false;
        }
    }

    function _compile_custom_function($function, $modifiers, $arguments, &$_result)
    {
        if (!function_exists('compile_compile_custom_function'))
        {
            require_once(TEMPLATE_LITE_DIR . "internal/compile.compile_custom_function.php");
        }
        return compile_compile_custom_function($function, $modifiers, $arguments, $_result, $this);
    }

    function _compile_custom_block($function, $modifiers, $arguments, &$_result)
    {
        if (!function_exists('compile_compile_custom_block'))
        {
            require_once(TEMPLATE_LITE_DIR . "internal/compile.compile_custom_block.php");
        }
        return compile_compile_custom_block($function, $modifiers, $arguments, $_result, $this);
    }

    function _compile_if($arguments, $elseif = false, $while = false)
    {
        if (!function_exists('compile_compile_if'))
        {
            require_once(TEMPLATE_LITE_DIR . "internal/compile.compile_if.php");
        }
        return compile_compile_if($arguments, $elseif, $while, $this);
    }

    function _parse_is_expr($is_arg, $_arg)
    {
        if (!function_exists('compile_parse_is_expr'))
        {
            require_once(TEMPLATE_LITE_DIR . "internal/compile.parse_is_expr.php");
        }
        return compile_parse_is_expr($is_arg, $_arg, $this);
    }

    function _compile_config($variable)
    {
        if (!function_exists('compile_compile_config'))
        {
            require_once(TEMPLATE_LITE_DIR . "internal/compile.compile_config.php");
        }
        return compile_compile_config($variable, $this);
    }

    function _dequote($string)
    {
        if (($string{0} == "'" || $string{0} == '"') && $string{strlen($string)-1} == $string{0})
        {
            return substr($string, 1, -1);
        }
        else
        {
            return $string;
        }
    }

    function _parse_arguments($arguments)
    {
        $_match        = array();
        $_result    = array();
        $_variables    = array();
        preg_match_all('/(?:' . $this->_qstr_regexp . ' | (?>[^"\'=\s]+))+|[=]/x', $arguments, $_match);
        /*
           Parse state:
             0 - expecting attribute name
             1 - expecting '='
             2 - expecting attribute value (not '=')
        */
        $state = 0;
        foreach($_match[0] as $value)
        {
            switch($state) {
                case 0:
                    // valid attribute name
                    if (is_string($value))
                    {
                        $a_name = $value;
                        $state = 1;
                    }
                    else
                    {
                        $this->trigger_error("invalid attribute name: '$token'", E_USER_ERROR, __FILE__, __LINE__);
                    }
                    break;
                case 1:
                    if ($value == '=')
                    {
                        $state = 2;
                    }
                    else
                    {
                        $this->trigger_error("expecting '=' after '$last_value'", E_USER_ERROR, __FILE__, __LINE__);
                    }
                    break;
                case 2:
                    if ($value != '=')
                    {
                        if ($value == 'yes' || $value == 'on' || $value == 'true')
                        {
                            $value = true;
                        }
                        elseif ($value == 'no' || $value == 'off' || $value == 'false')
                        {
                            $value = false;
                        }
                        elseif ($value == 'null')
                        {
                            $value = null;
                        }

                        if(!preg_match_all('/(?:(' . $this->_var_regexp . '|' . $this->_svar_regexp . ')(' . $this->_mod_regexp . '*))(?:\s+(.*))?/xs', $value, $_variables))
                        {
                            $_result[$a_name] = $value;
                        }
                        else
                        {
                            $_result[$a_name] = $this->_parse_variables($_variables[1], $_variables[2]);
                        }
                        $state = 0;
                    }
                    else
                    {
                        $this->trigger_error("'=' cannot be an attribute value", E_USER_ERROR, __FILE__, __LINE__);
                    }
                    break;
            }
            $last_value = $value;
        }
        if($state != 0)
        {
            if($state == 1)
            {
                $this->trigger_error("expecting '=' after attribute name '$last_value'", E_USER_ERROR, __FILE__, __LINE__);
            }
            else
            {
                $this->trigger_error("missing attribute value", E_USER_ERROR, __FILE__, __LINE__);
            }
        }
        return $_result;
    }

    function _parse_variables($variables, $modifiers)
    {
        $_result = "";
        foreach($variables as $key => $value)
        {
            $tag_variable = trim($variables[$key]);
            if(!empty($this->default_modifiers) && !preg_match('!(^|\|)templatelite:nodefaults($|\|)!',$modifiers[$key]))
            {
                $_default_mod_string = implode('|',(array)$this->default_modifiers);
                $modifiers[$key] = empty($modifiers[$key]) ? $_default_mod_string : $_default_mod_string . '|' . $modifiers[$key];
            }
            if (empty($modifiers[$key]))
            {
                $_result .= $this->_parse_variable($tag_variable).'.';
            }
            else
            {
                $_result .= $this->_parse_modifier($this->_parse_variable($tag_variable), $modifiers[$key]).'.';
            }
        }
        return substr($_result, 0, -1);
    }

    function _parse_variable($variable)
    {
        // replace variable with value
        if ($variable{0} == "\$")
        {
            // replace the variable
            return $this->_compile_variable($variable);
        }
        elseif ($variable{0} == '#')
        {
            // replace the config variable
            return $this->_compile_config($variable);
        }
        elseif ($variable{0} == '"')
        {
            // expand the quotes to pull any variables out of it
            // fortunately variables inside of a quote aren't fancy, no modifiers, no quotes
            //   just get everything from the $ to the ending space and parse it
            // if the $ is escaped, then we won't expand it
            $_result = "";
            preg_match_all('/(?:[^\\\]' . $this->_dvar_regexp . ')/', substr($variable, 1, -1), $_expand);  // old match 
//            preg_match_all('/(?:[^\\\]' . $this->_dvar_regexp . '[^\\\])/', $variable, $_expand);
            $_expand = array_unique($_expand[0]);
            foreach($_expand as $key => $value)
            {
                $_expand[$key] = trim($value);
                if (strpos($_expand[$key], '$') > 0)
                {
                    $_expand[$key] = substr($_expand[$key], strpos($_expand[$key], '$'));
                }
            }
            $_result = $variable;
            foreach($_expand as $value)
            {
                $value = trim($value);
                $_result = str_replace($value, '" . ' . $this->_parse_variable($value) . ' . "', $_result);
            }
            $_result = str_replace("`", "", $_result);
            return $_result;
        }
        elseif ($variable{0} == "'")
        {
            // return the value just as it is
            return $variable;
        }
        elseif ($variable{0} == "%")
        {
            return $this->_parse_section_prop($variable);
        }
        else
        {
            // return it as is; i believe that there was a reason before that i did not just return it as is,
            // but i forgot what that reason is ...
            // the reason i return the variable 'as is' right now is so that unquoted literals are allowed
            return $variable;
        }
    }

    function _parse_section_prop($section_prop_expr)
    {
        $parts = explode('|', $section_prop_expr, 2);
        $var_ref = $parts[0];
        $modifiers = isset($parts[1]) ? $parts[1] : '';

        preg_match('!%(\w+)\.(\w+)%!', $var_ref, $match);
        $section_name = $match[1];
        $prop_name = $match[2];

        $output = "\$this->_sections['$section_name']['$prop_name']";

        $this->_parse_modifier($output, $modifiers);

        return $output;
    }

    function _compile_variable($variable)
    {
        $_result    = "";

        // remove the $
        $variable = substr($variable, 1);

        // get [foo] and .foo and (...) pieces
        preg_match_all('!(?:^\w+)|(?:' . $this->_var_bracket_regexp . ')|\.\$?\w+|\S+!', $variable, $_match);
        $variable = $_match[0];
        $var_name = array_shift($variable);

        if ($var_name == $this->reserved_template_varname)
        {
            if ($variable[0]{0} == '[' || $variable[0]{0} == '.')
            {
                $find = array("[", "]", ".");
                switch(strtoupper(str_replace($find, "", $variable[0])))
                {
                    case 'GET':
                        $_result = "\$_GET";
                        break;
                    case 'POST':
                        $_result = "\$_POST";
                        break;
                    case 'COOKIE':
                        $_result = "\$_COOKIE";
                        break;
                    case 'ENV':
                        $_result = "\$_ENV";
                        break;
                    case 'SERVER':
                        $_result = "\$_SERVER";
                        break;
                    case 'SESSION':
                        $_result = "\$_SESSION";
                        break;
                    case 'NOW':
                        $_result = "time()";
                        break;
                    case 'SECTION':
                        $_result = "\$this->_sections";
                        break;
                    case 'LDELIM':
                        $_result = "\$this->left_delimiter";
                        break;
                    case 'RDELIM':
                        $_result = "\$this->right_delimiter";
                        break;
                    case 'VERSION':
                        $_result = "\$this->_version";
                        break;
                    case 'CONFIG':
                        $_result = "\$this->_confs";
                        break;
                    case 'TEMPLATE':
                        $_result = "\$this->_file";
                        break;
                    case 'CONST':
                        $constant = str_replace($find, "", $_match[0][2]);
                        $_result = "constant('$constant')";
                        $variable = array();
                        break;
                    default:
                        $_var_name = str_replace($find, "", $variable[0]);
                        $_result = "\$this->_templatelite_vars['$_var_name']";
                        break;
                }
                array_shift($variable);
            }
            else
            {
                $this->trigger_error('$' . $var_name.implode('', $variable) . ' is an invalid $templatelite reference', E_USER_ERROR, __FILE__, __LINE__);
            }
        }
        else
        {
            $_result = "\$this->_vars['$var_name']";
        }

        foreach ($variable as $var)
        {
            if ($var{0} == '[')
            {
                $var = substr($var, 1, -1);
                if (is_numeric($var))
                {
                    $_result .= "[$var]";
                }
                elseif ($var{0} == '$')
                {
                    $_result .= "[" . $this->_compile_variable($var) . "]";
                }
                elseif ($var{0} == '#')
                {
                    $_result .= "[" . $this->_compile_config($var) . "]";
                }
                else
                {
//                    $_result .= "['$var']";
                    $parts = explode('.', $var);
                    $section = $parts[0];
                    $section_prop = isset($parts[1]) ? $parts[1] : 'index';
                    $_result .= "[\$this->_sections['$section']['$section_prop']]";
                }
            }
            else if ($var{0} == '.')
            {
                   if ($var{1} == '$')
                {
                       $_result .= "[\$this->_TPL['" . substr($var, 2) . "']]";
                }
                   else
                {
                       $_result .= "['" . substr($var, 1) . "']";
                }
            }
            else if (substr($var,0,2) == '->')
            {
                if(substr($var,2,2) == '__')
                {
                    $this->trigger_error('call to internal object members is not allowed', E_USER_ERROR, __FILE__, __LINE__);
                }
                else if (substr($var, 2, 1) == '$')
                {
                    $_output .= '->{(($var=$this->_TPL[\''.substr($var,3).'\']) && substr($var,0,2)!=\'__\') ? $_var : $this->trigger_error("cannot access property \\"$var\\"")}';
                }
            }
            else
            {
                $this->trigger_error('$' . $var_name.implode('', $variable) . ' is an invalid reference', E_USER_ERROR, __FILE__, __LINE__);
            }
        }
        return $_result;
    }

    function _parse_modifier($variable, $modifiers)
    {
        $_match        = array();
        $_mods        = array();        // stores all modifiers
        $_args        = array();        // modifier arguments

        preg_match_all('!\|(@?\w+)((?>:(?:'. $this->_qstr_regexp . '|[^|]+))*)!', '|' . $modifiers, $_match);
        list(, $_mods, $_args) = $_match;

        $count_mods = count($_mods);
        for ($i = 0, $for_max = $count_mods; $i < $for_max; $i++)
        {
            preg_match_all('!:(' . $this->_qstr_regexp . '|[^:]+)!', $_args[$i], $_match);
            $_arg = $_match[1];

            if ($_mods[$i]{0} == '@')
            {
                $_mods[$i] = substr($_mods[$i], 1);
                $_map_array = 0;
            } else {
                $_map_array = 1;
            }

            foreach($_arg as $key => $value)
            {
                $_arg[$key] = $this->_parse_variable($value);
            }

            if ($this->_plugin_exists($_mods[$i], "modifier") || function_exists($_mods[$i]))
            {
                if (count($_arg) > 0)
                {
                    $_arg = ', '.implode(', ', $_arg);
                }
                else
                {
                    $_arg = '';
                }

                $php_function = "PHP";
                if ($this->_plugin_exists($_mods[$i], "modifier"))
                {
                    $php_function = "plugin";
                }
                $variable = "\$this->_run_modifier($variable, '$_mods[$i]', '$php_function', $_map_array$_arg)";
            }
            else
            {
                $variable = "\$this->trigger_error(\"'" . $_mods[$i] . "' modifier does not exist\", E_USER_NOTICE, __FILE__, __LINE__);";
            }
        }
        return $variable;
    }

    function _plugin_exists($function, $type)
    {
        // check for object functions
        if (isset($this->_plugins[$type][$function]) && is_array($this->_plugins[$type][$function]) && is_object($this->_plugins[$type][$function][0]) && method_exists($this->_plugins[$type][$function][0], $this->_plugins[$type][$function][1]))
        {
            return '$this->_plugins[\'' . $type . '\'][\'' . $function . '\'][0]->' . $this->_plugins[$type][$function][1];
        }
        // check for standard functions
        if (isset($this->_plugins[$type][$function]) && function_exists($this->_plugins[$type][$function]))
        {
            return $this->_plugins[$type][$function];
        }
        // check for a plugin in the plugin directory
        if (file_exists($this->_get_plugin_dir($type . '.' . $function . '.php') . $type . '.' . $function . '.php'))
        {
            require_once($this->_get_plugin_dir($type . '.' . $function . '.php') . $type . '.' . $function . '.php');
            if (function_exists('tpl_' . $type . '_' . $function))
            {
                $this->_require_stack[$type . '.' . $function . '.php'] = array($type, $function, 'tpl_' . $type . '_' . $function);
                return ('tpl_' . $type . '_' . $function);
            }
        }
        return false;
    }

    function _load_filters()
    {
        if (count($this->_plugins['prefilter']) > 0)
        {
            foreach ($this->_plugins['prefilter'] as $filter_name => $prefilter)
            {
                if (!function_exists($prefilter))
                {
                    @include_once( $this->_get_plugin_dir("prefilter." . $filter_name . ".php") . "prefilter." . $filter_name . ".php");
                }
            }
        }
        if (count($this->_plugins['postfilter']) > 0)
        {
            foreach ($this->_plugins['postfilter'] as $filter_name => $postfilter)
            {
                if (!function_exists($postfilter))
                {
                    @include_once( $this->_get_plugin_dir("postfilter." . $filter_name . ".php") . "postfilter." . $filter_name . ".php");
                }
            }
        }
    }
}

?>
